Fire-retardant compositions



U United-- States Patent Uihce Patented Feb. 15, 1955 FIRERETARDANT COMPOSITIONS Ivan V. Wilson, Wakefield, and Ralph Maroita, Malden, Mass., assignors to Monsanto Chemical Company, St. Louis, Mo., a corporation of Delaware No Drawing. Application August 31, 1950, Serial No. 182,632

16 Claims. (Cl. 260-6) The present invention relates to fire-retardant compositions, and it more particularly relates to potentially intumescing; fire-retardant water base coating compositions for the coating of combustible or heat-deformable substrates to protect such substrates from fire or heat, and, also, for coating a wide variety of substrates. to prevent iiame propagation.

It has been proposed heretofore to employ various types of water-soluble phosphates in water base coating compositions for the purpose of forming coatings which intumesce or form a cellular char when exposed to a direct flame or high temperatures. Coatings produced from such compositions while satisfactory for limited purposes are not satisfactory when they must be subjected to frequent washingsmr high humidity conditions since the water-solublgphosphates are leached out of the coating under such conditions and the coating loses its fire-retardant properties.

It has also been proposed to use urea and formaldehyde or partially condensed urea-formaldehyde condensation products as film-forming agents or binding materials for the water-soluble phosphates to give some permanency to the coating and thus protect the substrate and also provide an ornamental finish thereon. Thermosetting resins of the amine-aldehyde type, of which urea-formaldehyde condensation products are representative, have the disadvantage of becoming brittle when they are highly polymerized with the result that the coating cracks and checks, and not only presents an undesirable appearance but also tends to lose its effectiveness for protecting the underlying substrate from fire or heat.

Various suggestions have been made to overcome the above mentioned deficiencies of fire-retardant water base coating compositions containing the water-soluble phosphotos and urea-formaldehyde condensation products. particularly with the view of improving the water-resistance or the check or crack resistance of the coatings,

but insofar as is presently known none of these suggestions have proved entirely successful in commercial practice.

It is one object of the present invention to provide improved potentially intumescing fire-retardant compositions.

It is a further object of this invention to provide fireretardant water base coating compositions which form coatings having excellent resistance to checking and cracking and also excellent resistance to washing and high humidity conditions without appreciable loss in fire-retardant properties.

it is a further object of this invention to provide fireretardant water base coating compositions which form coatings having improved intumescing properties when subjected to heat or an open flame.

Still further objects and advantages of this invention will appear in the following description and the appended claims.

The fire-retardant compositions of this invention include dry or substantially dry mixtures and water dispersions of such mixtures. The'dry or substantially dry mixtures comprise, in general, a solid, water-dispersible, heatconvertible, aminoplast or amino-aldehyde condensation product, preferably a water-dispersible urea-formaldehyde condensation product; a water-insoluble reaction product of phosphoryl chloride and ammonia and a cold waterinsoluble polyhydric compound such as a water-insoluble polypentaerythritol, for example, dipentaerythritol or tripentaerythritol or an unhydrolyzed starch such as unhydrolyzed corn starch or mixturesthereof with a hydrolyzed starch such as hydrolyzed corn starch. The compositions preferably also contain fibrous materials as, for example, proteinaceous fibers suchjasyvoolii'fiock, vegetable fibers such as cotton or lirienvlioclt, pegenerated cellulose fibers and minerahfiberssuch..as.asbestos.fibers. Of these fibrous materials proteinaceous fibers such as wool flock are preferred because they improve the intumescing properties of the composition whereas the other fibrous materials decrease the intumescence of the composition to some extent. The fibrous materials when used serve to minimize the checking and cracking tendencies of the aminoplast coatings.

The compositions may also contain non-combustible plasticizers for the aminoplast. The aryl sulionamides and substituted aryl sulfonamides such as N-ethyl toluene sulfonamide are particularly preferred for this purpose because of their high compatibility with the aminoplast resins. The compositions may also contain various materials which are commonly used in coatings as, for example, inorganic and organic pigments, and thickening or dispersing agents such as ammonium caseinate, soya protein, polyvinyl alcohol, carboxyl methyl-cellulose and the like. The dry or substantially dry compositions described above have a shelf life of several months.

The liquid coating compositions comprise the above described ingredients dispersed in water. These compositions may be prepared in various ways, for example, by premixing the dry ingredients and then adding the mixed ingredients to the water, or the various ingredients may be added to the water or a water dispersion of the aminoplast with stirring to form the dispersion. The aminoplast may be prepared in water and the ingredients added thereto or the ingredients used in preparing the aminoplast, for example, urea and formaldehyde may be added to the water without any special effort being made to form a condensate. The procedure of preparing a preformed aminoplast is preferred since in such instances the aldehyde used in preparing the aminoplast is chemically combined with urea or some other amino compound and the composition does not give ofi obnoxious aldehyde fumes. On the other hand, if the ingredients used in preparing the aminoplast are added to water, without any attempt to cause chemical combination of the aldehyde with the amino compounds aldehyde fumes are liberated and this is undesirable in certain applications. Moreover, a coating prepared from the latter solution exhibits greater water sensitivity than a coating prepared from a preformed aminoplast. The liquid coating compositions have satisfactory stability for coating purposes and generally remain fluid for a period of 8 to 20 hours or more which is sufiiciently ample for conventional methods of application such as spraying, brushing, dipping or roll coating or the like.

The water-dispersible, heat-convertible aminoplasts or amino-aldehyde condensation products employed in the compositions of this invention include a wide variety of materials which are prepared from aldehydes and'an organic compound containing at least one and preferably two amino groups having at least two and preferably three replaceable hydrogen atoms. The aminoplasts employed in the compositions of this invention are preferably water-soluble but should at least be water-dispersible, that is, they should not be so far condensed as to be'non-dispersible in water, and they should be capable of forming a substantially continuous film on drying. They should also be capable of polymerizing or curing at normal room temperatures or elevated temperatures in the presence of the other ingredients of the composition to form water-insoluble films.

The preferred aminoplasts for use in the compositions of this invention are the water'dispersible, heat convertible, urea-formaldehyde condensation products, and particularly the condensation products of 1 molecular proportion of urea and 1.6 to 2.25 molecular proportions of formaldehyde. Such condensation products may be used in the form of a dry solid or as a water dispersion or water solution.

As examples of other aminoplasts which are useful as the film-forming ingredient in the compositions of this invention may be mentioned the waterdispersible, heat convertible condensation products of an aldehyde with thiourea, guanidine, cyanamide, dicyandiamide and amino triazines having at least two amino. groups as, for example, melamine, 2-ehloro-4,6 d am1no-1,3,5 triazine, 2-hydroxy-4,6-diamino-1,3,5 trtazme, alkyl guanamines, aryl guanamines and the like. In general, the useful aminoplasts are prepared by partially condensing formaldehyde with amino compounds containing from 1 to 9 carbon atoms and having the grouping where Y is a member selected from the class consisting of O, S and N--, and where N represents a nitrogen atom having two single valences attached to separate hydrogen or carbon atoms or where the two free valences hyde condensation products. Such alkylated derivatives may be prepared, for example, by reacting the simple condensation products with an'alcohol according to procedures well known inlhe prior art and as illustrated in V the patent to Widmer, No. 2,197,357.

The aminop lasts may be prepared by using various aldehydes instead of formaldehyde. As examples of these may be mentioned acetaldehydc, propionaldehyde, furfural, glyoxal and the like. However, formaldehyde and water-soluble polymers of formaldehyde such as paraformaldehyde not only are cheaper but also 'give superior aminoplasts for the purposes of this invention and are therefore preferred.

The water-insoluble reaction products of phosphoryl chloride and ammonia, as employed in the compositions 1' this invention, serve as fire-retardant or fire-resistant materials,"although they do not actually intumesce in the absence of other ingredients when exposed to ah open flame. These reaction products may be prepared in various ways. However, the manner in which they are prepared has some effect on their usefulness.

The reaction product of phosphoryl chloride and ammonia which is preferably used in the compositions of this invention is the product prepared by reacting phosphoryl chloride and ammonia, preferably in an organic solvent which has a normal boiling point above 200 C. at atmospheric pressure, after which the product is subjected to a temperature above 155 C. for a period of time sufiicient to convert it to the water-insoluble state, preferably while it is still suspended in the organic solvent. The resulting product is separated from the organic solvent as by filtration or centrifuging and then evaporating the solvent, and has been designated and is referred to herein as polyphosphorylamide. It is a water-insoluble white powder having a substantially neutral or alkaline reaction. Polyphosphorylamide per se is infusible except'when exposed to'very great heat. The atomicratio of nitrogen to phosphorous in the product is generally above 1.2:1 and preferably within the range of 1.50:1 to 2.021. The preparation of polyphosphorylamide is described in greater detail in the copending application of John E. Malowan and Forest R. Hurley, Serial No. 68,402. filed December 30, 1948. now Patent No. 2,596,935 issued May 13, 1952.

A wide variety of water-insoluble polyhydric compounds may be used in the compositions of this invention.

e polypentaerythritols and starches are two types of materials which come within this class of compounds and which are particularly useful and preferred in the compositions described herein. The polypentaerythritol may be used without the starch or the starch may be used without the polypentaerythritol. However, best results are usually obtained by using both of these ingredrents in the compositions. A weight ratio between 10:1- and 1:10 is especially useful in such cases. The

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polypentaerythritol'and starch do not give a coating having equivalent properties and for some purposes 1t is preferred to use the polypentaerythritols particularly when enhanced intumescing properties and water resistance are desired. Starch, on the other hand, is sometimes preferred since it is possible to replace a minor amount say up to 30% of the aminoplast with starch without materially detracting from the quality of the coating with regard to its fire-retardant properties.

The polypentaerythritol when used in the compositions herein described may be employed in its various polymeric forms, for example, as a dimer, trimer, etc. examples of polypentaerythritols may be mentioned dipenta'erythritol and tripentaerythritol and mixtures thereof. The polypentaerythritols perform two important functions in the compositions herein described. First of all they improve the intumescing. properties of the coating with the result that it is possible to obtain equivalent protection against heat or an open flame with a thinner coating. in the second place they serve to prevent checking and cracking of the coating, and being water-insoluble or substantially water-insoluble do not wash out'of the coating with the result that the coating remains resistant to checking and cracking and also retains its inturnescing properties after a substantial number of washings.

The unhydrolyzed starch, when used in the compositions of this invention has several important advantages for certain purposes. The unhydrolyzed starch is a cheap material and when low cost coatings are especially desired a considerable amount of starch say up to 250% by weight on the aminoplast solid of the composition may be used'without appreciably lowering the quality of the coating. The addition of starch to the coating also helps in improving the check and crack resistance of the coating. This is particulariy true when hydrolyzed starch is used. .However, hydrolyzed starch has relatively less water resistance than unhydrolyzed starch and for this' reason, when hydrolyzed starch is used, a mixture of the two types of starch is preferred if a more water resistant coating is to be obtained. It is preferred in using such mixtures to employ a major portion of unhydrolyzed starch. that is 55% or more and aminor portion, thateis, ,or less of hydrolyzed starch, based on the starch mixture. It is not necessary to add the starch as a separate irrgredient since satisfactory results may be obtained by adding the starch to the ingredients used in preparing, the aminoplast, namely the aldehyde and the amino compound in water, and then condensing the resulting mixture to form'a water-dispersible product. As examples of unhydrolyzed starches which are useful in the compositions of this invention may be mentioned unhydrolyzed corn, waxy maize, rice, wheat.

- tapioca, sweet potato, Irish potato and sorghum starches.

These starches are readiiy hydrolyzed by cooking them in water and in the hydrolyzed condition are suitable as the hydrolyzed starchjportion when starch mixtures are employed herein. ,7

The liquid coating compositions of this invention'dry down at room temperature to form films which are substantially water resistantat the end of a 48 hour drying period, and are characterized by good adhesion to combustible substrates .such as wood, plywood. 'fibreboard,

' acoustical fibretile and certain types of inflammable or heat deformable plastics. The liquid compositions may also be applied to various heat deformable substrates such as thermoplastic resins, and also to iron. brass: aluminum and other metal substrates to provide protection against heat deformation and flame propagation. if desired, thecoatings may be heated or baked to shorten the period of curing or polymerization of the amino plast: The coatings formed from these compositions possess the property of intumescing when exposed to an open flame or to heat and do not appreciably lose this property even when the coating is washed with water periodically or exposed to high humidity conditions over the normal life of the coating. By intumesce" is meant the property of frothing or putting in such a manner as to produce a considerably swollen, solid cellular residue, which in itself is practically non-combustible. Such residue is sufficiently continuous and adherent to protect the substrate from combustion or the deleterious effects of heat and accomplishes this result by preventing access of air to the substrate and at the same time insulating the substrate from heat;

The compositions which contain a. combination of the aminoplast, the water-insoluble reaction product of phosphoryl chloride and ammonia and the polypentaerythr tol or starch provides greater intumescence than s possible with a composition containing only a combination of the aminoplast and the water-insoluble reaction product ot phosphoryl chloride and ammonia. Moreover, a coat1ng is obtained which is more resistant to checking and cracking and which is also highly resistant to leaching with water.

A further understanding of the compositions of this invention will be obtained from the following specific examples which are intended to illustrate several of the most desirable compositions but are not intended to limit the scope of the invention, parts and percentages being .by weight unless otherwise specified.

Example 1 Fifty parts of a water solution of urea-formaldehyde condensation product was first prepared by heating 1 mol of urea and 2 mols of formaldehyde under slightly acidic conditions in the presence of sufficient water to provide a solution containing 50% solids, after which the solution was adjusted to a pH of 7. Twelve and five-tenths parts of finely divided water-insoluble y amide-and 12.5 parts of finely divided dipentaeryth'fittilwere stirred into the urea-formaldehyde solution along ,with 25 parts of water until a homogeneous suspension was obtained. The resulting composition contained 25% urea-formaldehyde solids, 12.5% polyphosphorylamide solids and 12.5% dipentaerythritol solids. The composition remained fluid and useable for 8 hours. The above composition was applied to maple boards by brushing. After allowing the coating to age for two days, the urea-formaldehyde condensation product had cured or polymerized sufiiciently to form a water-insoluble film. A portion of the coated board was exposed to the direct flame of a Bunsen burner for five minutes, whereupon the coating swelled and intumesced to form a non-combustible cellular char which acted as an insulating blanket and an efiective oxygen barrier. Upon removing the Bunsen burner flame and scraping away the pulled char of the coating it was noted that the underlying wood was not damaged by the flame or heat.

A duplicate coated board (not exposed to flame) was allowed to remain submerged for 10 minutes in running water and then dried overnight at room temperature. This piece was then exposed to the direct flame of a 6 suificient to provide 20 grams of paint solids per square foot of board surface. After the coating had been aged for a period of one week, the coated board was subjected to Federal Specification Fire Test SS-A-1l8a Amendment 1. Classification F of this test for slow burning materials was easily passed.

The coatings produced from the composition described in this example exhibit superior resistance to checking and cracking and this is believed to be due to the presence of the wool flock or possibly the wool flock in combination with the dipentaerythritol. It was noted that these coatings exhibited substantially the same intumescence as the coatings produced from the compositions of Example I. The titanium dioxide was used to give a pigmentei coating and can be omitted if a clear coating is desire Example III A coating composition was prepared by stirring the following ingredients:

1 Prepared by condensing 1 mol of urea. with 2.25 mole of formaldehyde in water.

The resulting homogeneous composition remained fiuid and useable for a period of 12 hours. This paint was applied to a poplar plywood in an amount sufficient to provide a coating containing 19 grams of solids per square 1 foot of wood surface. After the coating had been allowed Bunsen burner for 5 minutes, whereupon the coating in- Example II A white paint was prepared by stirring the following ingredients:

Parts Spray dried urea-formaldehyde condensation product Water-dispersible powder 20 Water-insoluble polyphosphorylamide 8 Dipentaerythritol 14 Wool flock 4 TiOr (as a pigment) 4 Water Prepared by condensing 1 mol of uren and 1.84 mole-0! formaldehyde.

This: was :1 commercial grade of wool tlhers averntrint: lfig inch in length.

The homogeneous paint thus obtained remained fluid and useable for a period of 8 hours. This paint was apto age for 1 week at a temperature of 77 F. and a relative humidi ty of 50%, the flame of a Bunsen burner was rmpmgeddtrectly on the coating for a period of 5 minutes. The coating swelled or intumesced to a voluminous, carbonaceous char which localized the flame and protected the underlying surface by preventing penetration of heat and excluding oxygen.

The tripentaerythritol performed in somewhat the same manner as the dipentaerythritol of Example I, but contributed slightly less intumescence.

The N-ethyl toluene sulfonamide served to further reduce any tendency of the coating to check or crack without detracting appreciably from the tire retardant and mtumescing properties of the coating.

Example IV A coating composition was prepared by stirring the following ingredients:

Prepared by condensing 1 mol of the sultonsmlde with 2 mole of the ethylene oxide.

The resulting homogeneous composition remained fluid and useable for a period of 12 hours. This paint was applied to fibreboard by spraying the paint in an amount sufficient to provide 25 grams of paint solids per square foot of board surface. After the coating had been aged for 24 hours, the coated board was subjected to Federal Specification Fire Test SS-Al 18a Amendment 1. Classification F of this test for slow burning materials was passed.

The coatings produced from the composition described plied to fibreboard by spraying the paint in an amount in this example exhibit superior resistance to checking and cracking and have good resistance to washing with cold water.

The coating compositions prepared in accordance with the preceding examples contain 25%, 20%, 17.6% and 12.9%, respectively, of urea-formaldehyde solids but it is to be understood that the liquid compositions of this invention are not limited to these percentages of the aminoplast. In general, the liquid compositions contain from to 35% by weight of the aminoplast, although even smaller amounts may be used if starch is also employed and up to 40% by weight may be used ifthe viscosity of the solution is not too high to be ObjCCtlOilable. In most instances, however, it is preferred to employ liquid coating compositions comprising from 5 to 25% by weight of the aminoplast.

The water-insoluble polyphosphorylamide according to the preceding examples is employed in amounts of 50%, 40.2%, 40.2% and 33.3%, by weight, respectively, based on the weight of the aminoplast in the composition. These amounts may be varied to some extent depending upon various factors such as the thickness of coating, and the substrate to be protected. In general, the waterinsoluble reaction products of phosphoryl chloride and ammonia, of which polyphosphorylamide is illustrative, are employed in amounts varying between and 100% by weight, based on the aminoplast. However, for most purposes a preferred range is to 60% by weight, based on the aminoplast.

The water-insoluble polyhydric compound such as starch or the polypentaerythritols employed in the foregoing examples is illustrated as varying between about 59 and 177% by weight, based on the aminoplast. For most purposes these amounts may be varied somewhat depending upon the particular compound used without reducing the quality of the coating. Thus, in general, the polypentaerythritol is employed in amounts varying between about 20 and 150% by weight, based on the aminoplast. Best results are usually obtained, however, by employing from to 80% by weight of the polypentaerythritol. based on the aminoplast, and these amounts are preferred. When starch is used as illustrated in Example IV it is generally employed in amounts varying between 30 and 250% on the weight of the aminoplast, although when a polypentaerythritol is also employed amounts as low as 5% may be used. For best results, the starch is preferably employed in amounts ranging from 50 to 200% on the weight of the aminoplast. From the foregoing it will be seen that the waterinsoluble polyhydric compound may be used in amounts varying between about 20 and 250% on the weight of the aminoplast depending on the particular polyhydric compound which is used in the composition.

The wool flock or other fibrous material when used in the compositions, as illustrated in Examples II, III

and IV, are generally employed in amounts varying beitween 3 and by weight on the aminoplast. Such amounts provide coatings which have a high degree of intumescence and superior check and crack resistance. For most purposes amounts within the range of 10 to 25% by weight on the aminoplast are preferred.

In all of the foregoing examples the aminoplast and the various additives may be premixed in the dry or sub stantially dry state before they are mixed with water to form the coating composition. This is preferable in 'most instances since the dry ingredients have a relatively long shelf life and may be premixed and stored for a considerable period of time before they are actually. employed in brushing and spraying formulations. Thus. the dry ingredients remain stable over a period of 2 to 3 months whereas the liquid coating compositions generally must be used within a period of 8 to 20 hours.

it will be understood that the amounts of the various ingredients used in the liquid coating compositions of this invention must be adjusted so that the final composition is still liquid and capable of being applied to a substrate for coating purposes. Compositions containing from 10 to by weight of total solids are generally capable of being brushed or sprayed whereas compositions containing from 50 to solids may be applied by roll coating or the like. In general, the coating compositions of this invention comprise from about 10 to 75% solids by weight and from about 90 to 25% by weight of water. For most purposes. coating compositions comprising from about 20 to 60% solids by weight and from to 40% water are preferred.

' scrubbed tile for a period of 5 minutes.

Example V A fire-retardant dry composition was prepared by mixing the following ingredients:

Parts Spray dried urea-formaldehyde condensation product, water-dispersible powder 26.2 Water-insoluble polyphosphorylamide 8.8 Dipentaerythritol 15.3 I Wool flock 3.5 Corn starch (unhydrolyzed) 31.5 Rutile TiOz pigment 6.0 N-ethyl toluene sulfonamide 2.9 p-Toluene sultonamide 2.9

p-Toluene sulfonamide-ethylene oxide condensation product 1 Irernsred by condensing 1 mo]. of the sulfonamide with 2 mols of ethylene oxide.

In preparing the above mixture all of the ingredients except the sulfonamides and the ethylene oxide condensation product thereof were introduced into a ribbonblender type mixer. The sulfonamides were all melted together at 50 to 75 C. and then sprayed slowly in the form of a mist into the ingredients in the mixer while the mixing blades were operating. After the sulfonamides were added, the mixing was continued for 30 minutes to insure the preparation of a dry, substantially homogeneous powder. The resulting mixture had a shelf life of two months when stored in a dry condition at normal room temperatures.

The above composition was used to form a liquid coating composition by mixing 1 part of the dry mixture together with 1 part of water until a smooth paint dispersion was obtained. The resulting paint dispersion remained fluid and useable for a period of 16 hours. The paint was sprayed on vegetable fibre acoustical tiles in an amount sufficient to provide a coating consisting of 33 pounds of paint solids per 1000 square feet of substrate surface. The freshly coated tiles were immediately placed in an oven at 250 F. and were allowed to remain in the oven for a period of 10 minutes in order to dry and cure the coating. A representative 'sample of the coated tiles was conditioned for 24 hours at a temperature of 77 F. and a relative humidity of 50%, after which the flame of a Bunsen burner was impinged directly onto the surface of the tile for a period of 5 minutes. During this period the coating intumesced to form a voluminous, non-combustible, spongy char which prevented destruction of the tile. The uncoated tiles, on the other hand, are highly combustible and burn easily when exposed to a Bunsen flame.

Other samples of the coated tiles were subjected to the fire test described in the publication of the U. S. Department of Commerce entitled Commercial Standard CS 4249." was easily passed.

Another sample of the coated tile was tested for water resistance by keeping the surface of the tile wet with water and scrubbing the surface with 2000 strokes of a onepound brush by the use of a H. A. Gardner standard washability machine. At the end of this period of time, the scrubbed coating had substantially the same appearance as the original coating. The flame of a Bunsen burner was impinged directly on the surface of the During this period of exposure to the flame the coating on the tile intumesced to form a voluminous non-combustible spongy char which prevented destruction of the tile.

The dry compositions of this invention, of which the composition of Example V is illustrative, generally comprise from about 10 to 70% by weight of a dry or substantially dry water-dispersible aminoplast as, for example, a urea-formaldehyde condensation product. The amounts of the water-insoluble reaction product of phosphoryl chloride and ammonia and the polypentaerythritol or starch used in relation to the aminoplast have already been described in the descriptive matter following Example lV. When starch is used as illustrated in Example V, the compositions comprise from about 6 to 65% by weight of the starch and it is possible under such circumstances to use smaller amounts of the aminoplast, for example, from about 5 to 30% by weight of the aminoplast.

The amount of wool flock or other fibrous material used in the dry compositions may vary between about Test 6.2:9, Flame resistant-finished surface 3 to 35% by weight on the aminoplast. Of course, it is understood that the fibrous material may be omitted entirely.

When non-combustible plasticizers such as the sulfonamides illustrated in the examples are emplo ed in the dry or liquid compositions they are genera y used in amounts varying between about and 50% by weight on the aminoplast. For best results amounts varying between 20 and 40% by weight on the aminoplast are preferred.

As examples of other non-combustible plasticizers which may be used instead of the aryl sulfonamides may densation product, (2) from to 10% on the weight of said condensation product of a water-insoluble reaction be mentioned triphenyl phosphate and chlorinated biv phenyls.

Although titanium dioxide is illustrated in some or the examples as a suitable pigment, it is possible, of course, to use other pigments of the inorganic or organic types instead of the titanium dioxide when a pigmented coating is desired. As examples of suitable inorganic pigments which are useful in this connection may be mentioned barytes, magnesium silicate, clay, calcium phosphate, magnesium ammonium phosphate, lead phosphate, Prussian Blue and the like. Suitable organic pigments include Lithol Red, Hausa Yellow and the like.

- Various modifications and changes may be made in the fire-retardant compositions of this invention as will be apparent to those skilled in the art to which the invention appertains without departing from the intent or spirit of the invention described herein. it is understood therefore that the invention is only to be limited by the scope of the appended claims.

What is claimed is:

1. A fire-retardant composition comprising (1) a waterdispersible, heat-convertible condensation product of an aldehyde and an amino compound containing from 1 to 9 carbon atoms and having the grouping where Y is a member selected from the class consisting of O, S and N- and where the free valences on the nirtogen atoms are attached to atoms selected from the group consisting of hydrogen and carbon atoms, (2) from 15 to 100%, on the weight of said condensation product, of a water-insoluble reaction product of phosphoryl chloride and ammonia, said reaction product having an atomic ratio of nitrogen to phosphorus within the range of 1.5:1 to :1, (3) from 20 to 250%, on the weight of said condensation product (1), of a cold-water-insoluble polyhydric compound selected from the group consisting of (a) a polypentaerythritol, (b) a mixture of a polypentaerythritol and unhydrolyzed starch, (c) a mixture of a polypentaerythritoi, unhydrolyzed starch and hydrolyzed starch, in which the unhydrolyzed starch comprises the major proportion of the starch materials, and (d) starch, the weight ratio of starch materials to polypentaerythritol in mixtures (11) and (0) being between 10:1 and 1:10, and (4) proteinaceous fibers in an amount of 3 to on the weight of said condensation product (1).

2. A substrate coated on at least one surface thereof with a water-resistant coating comprising (1) a polymerized condensation product of an aldehyde and an amino compound containing from 1 to 9 carbon atoms and having the grouping where Y is a member selected from the class consisting of O, S and N- and where the free valences on the nitrogen atoms are attached to atoms selected from the group consisting of hydrogen and carbon atoms, (2) from 15 to 100%, on the weight of said condensation product, of a water-insoluble reaction product of phosphoryl chloride and ammonia, said reaction product having an atomic ratio of nitrogen to phosphorus within the range of 1.5:1 to 20:1, (3) from 20 to 250%, on the weight of said condensation product (1), of a cold-water-insoluble polyhydric compound selected from the group consisting of (a) a polypentaerythritol, (b) a mixture of a polypentaerythritol and unhydrolzed starch and (c) a mixture or" a polypentaerythritol, unhydrolzed starch and hydrolyzed starch, in which the unhydrolzed starch comprises the maior proportion of the starch materials, and

product of phosphoryl chloride and ammonia, said reaction product having an atomic ratio of nitrogen to phosphorus within the range of 1.5:1 to 2.021, (3) from 20 to 250% on the weight of said condensation product of a cold water-insoluble polyhydric compound selected from the group consisting of (a) a polypentaerythritol, (b) a mixture of a polypentaerythritol and unhydrolyzed starch, (c) a mixture of a polypentaerythritol, unhydrolyzed starch and hydrolyzed starch, in which the unhydrolyzed starch comprises the ma or proportion of the starch materials, and (d) starch, the weight ratio of starch materials to polypentaerythritol in mixtures (b) and (0) being between 10:1 and 1:10, and (4) proteinaceous fibers in an amount of 3 to 35% on the weight of said condensation product (1).

4. A composition as in claim 3, but further characaeriied in that the proteinaceous fibers consist of wool 5. A fire-retardant composition comprising (1) a waterdispersible, heat-convertible urea-formaldehyde condensation product, (2) from 15 to 100% on the weight of said condensation product of a water-insoluble polyphosphorylamide having an atomic ratio of nitrogen to phosphorus within the range of 1.5:1 to 2.021, (3) from 20 to 150% on the weight of said condensation product of a cold water-insoluble polypentaerythritol and (4) proteinaceous fibers in an amount of 3 to 35% on the weight of said condensation product (1).

6. A composition as in claim 5, but further characterized in that the polypentaerythritol is dipentaerythritol.

7. A composition as in claim 5, but further characterized in that the polypentaerythritol is tripentaerythritol.

8. A composition according to claim 5, but further characterized in that the proteinaceous fibers consist of wool flock.

9. A fire-retardant composition comprising (i), a water-dispersible, heat convertible urea-formaldehyde condensation product, (2) from 15 to 100% on the weight of said condensation product of a water-insoluble polyphosphorylamide having an atomic ratio of nitrogen to phosphorus within the range of 1.5:1 to 20:1, (3) from 20 to 250% on the weight of said condensation product of a mixture of cold water-insoluble starch and a polypentaerythritol, said starch and polypentaerythritol being present in said mixture in a weight ratio between 10:1 and 1:10, and (4) proteinaceous fibers in an amount of 3( ti; 35% on the weight or said condensation product 10. A composition as in claim 9. but further characterized in that said proteinaceous fibers consist of wool flock.

11. A fire-retardant composition comprising l) a water-dispersible, heat convertible urea-formaldehyde condensation product, (2) from 15 to on the weight of said condensation product of a water-insoluble polyphosphorylamide having an atomic ratio of nitrogen to phosphorus within the range of 1.5:1 to 2.021, (3) from 20 to 250% on the weight of said condensation product of a cold water-insoluble polypentaerythritol and a mixture consisting of a major portion of unhydrolyzed starch and a minor proportion of hydrolyzed starch, said polypentaerythritol and starch mixture being present in a weight ratio between 10:1 and 1:10, and (4) proteinaceous fibers in an amount of 3 to 35% on the weight of said condensation product (1).

12. A composition as in claim 11, but further char- 1zactegized in that the proteinaceous fibers consist of wool 13. A fire-retardant composition comprising (1) a water-dispersible, heat convertible urea-formaldehyde condensation product, (2) from 15 to 100% on the weight of said condensation product of a water-insoluble polyphosphorylamide having an atomic ratio of nitrogen to phosphorus within the range of 1.5 :l to 20:1, (3) from 20 to 250% on the weight of said condensation product of a cold water-insoluble polyhydric compound selected from the group consisting of (a) a polypentaerythritol,

mouse 11 (b) a mixture of a polyp entaerythritol and unhydrolyzed starch, (c) a mixture of a poiypentaerythritoi, unhydrolyzed starch and hydrolyzed starch, in which the unhydrolyzcd starch comprises the major proportion of the starch materials, and (d starch, the weight ratio of starch materials to polypentaerythritol in mixtures (b) and (c) being between 10:1 and 1:10, (4) an aromatic J sulfonamide in an amount sufiicient to plasticize said condensation product and proteinaceous fibers in an amount of 3 to 35 on the weight of said condensation product (1 14. A substrate coated on at least one surface thereof with a potentially intumescing, water-resistant coating comprising (1) a poiymerized urea formaldehyde resin,*'

(2) from 15 to 100% on the weight of said resin of a water=insolubie polyphosphorylamide having an atomic ratio of nitrogen to phosphorus within the range of 1.5:1

to 2.0:1, (3) from 2040 250% on the weight'of said resin of a cold water-insoluble polyhydric compound selected 'from thetgroup consisting of (a) a polypentaerythritol, (b) a mixture of a polypentaerythritoi and unhydrolyzed starch, (c) a mixture of a polypentaerythritol, unhydrolyzed starch and hydrolyzed starch, in which the iunhydrolyzed starch comprises the major 'proportion of said starch materials, and (d) starch, the weight ratio of starch materials to polypcntaerythritol in mixtures (b) and (ckbcing between 1011 and 1:10, and (4) pro teinaceous fibers in an amount of 3 to 35% on the weight of said condensation product (1).

15. A fire-retardant wmposition comprising (1) a water dispersible, heat convertible urea formaldehyde condensation product, (2) from 15 to on the weight of said condensation-product of a water-insoluble References Cited in the 51 of this patent UNITEDJSTATES PATENTS 2,052,886 Leroy -4; Sept. 1, 1936 2,326,728 Schroy a- Aug 10, 1943 2,452,054 Jones et al. Oct. 26, 1948 -2,596,939 Nielsen et a1. May 13, 1952 n FOREIGN PATENTS 570,884 Great Britain July 26, 1945 OTHER REFERENCES Mellor, A Comprehensive Treatise on Inorganic and Theoretical Chemistry, Longmans, Green, 1928, vol. 8, page 707. 1 at 

1. A FIRE-RETARDANT COMPOSITION COMPRISING (1) WATERDISPERSIBLE, HEAT-CONVERTIBLE CONDENSATION PRODUCT OF AN ALDEHYDE AND AN AMINO COMPOUND CONTAINING FROM 1 TO 9 CARBON ATOMS AND HAVING THE GROUPING 